Phytolacca americana

Pokeberry shoots, cooked, boiled, drained, without salt

Nutritional value per 100 g (3.5 oz)
Energy	84 kJ (20 kcal)
Carbohydrates	3.1 g
Sugars	1.6 g
Dietary fiber	1.5 g
Fat	0.4 g
Protein	2.3 g
Vitamins
Vitamin A equiv. beta-carotene lutein zeaxanthin	(54%) 435 μg (48%) 5200 μg 1747 μg
Thiamine (B1)	(6%) 0.07 mg
Riboflavin (B2)	(21%) 0.25 mg
Niacin (B3)	(7%) 1.1 mg
Vitamin B6	(9%) 0.111 mg
Vitamin C	(99%) 82 mg
Vitamin K	(103%) 108 μg
Trace metals
Calcium	(5%) 53 mg
Iron	(9%) 1.2 mg
Magnesium	(4%) 14 mg
Manganese	(16%) 0.336 mg
Phosphorus	(5%) 33 mg
Potassium	(4%) 184 mg
Sodium	(1%) 18 mg
Link to USDA Database entry
Units μg = micrograms • mg = milligrams IU = International units
Percentages are roughly approximated using US recommendations for adults. Source: USDA Nutrient Database

American Pokeweed (Phytolacca americana) is a large semi-succulent herbaceous perennial plant growing up to 10 feet (3 metres) in height. It is native to eastern North America, the Midwest, and the Gulf Coast, with more scattered populations in the far West. It is also known as Virginia poke,^[1][2] American nightshade, cancer jalap, coakum, garget,^[2] inkberry, pigeon berry,^[1][2] pocan,^[2] pokeroot,^[1] pokeweed,^[1] pokeberry,^[1] redweed, scoke,^[2] red ink plant and chui xu shang lu (in Chinese medicine).^[1] Sometimes the plant is also referred to as poke sallet^[3] (or polk salad).^[4] Parts of this plant are highly toxic to livestock and humans, and it is considered a major pest by farmers. Nonetheless, some parts can be used as food or poison if properly prepared.

The plant has a large white taproot, green or red stems, and large, simple leaves. White flowers are followed by purple to almost black berries, which are a good food source for songbirds such as gray catbird, northern cardinal, brown thrasher, and northern mockingbird.

Morphology

Plant Type: Perennial herbaceous plant which can reach a height of 10 feet (3 metres), but is usually 4 feet (1.2 metres) to 6 feet (2 metres). However, the plant must be a few years old before the root grows large enough to support this size. The stem is often red as the plant matures. There is an upright, erect central stem early in the season, which changes to a spreading, horizontal form later in the season with the weight of the berries. Plant dies back to roots each winter. Stem has a chambered pith.

Leaves: The leaves are alternate with coarse texture with moderate porosity. Leaves can reach sixteen inches in length. Each leaf is entire. Leaves are medium green and smooth with what some characterize as an unpleasant odor.

Flowers: The flowers have 5 regular parts with upright stamens and are up to 0.2 inches (5 mm) wide. They have white petal-like sepals without true petals, on white pedicles and peduncles in an upright or drooping raceme, which darken as the plant fruits. Blooms first appear in early summer and continue into early fall.

Fruit: A shiny dark purple berry held in racemous clusters on pink pedicels with a pink peduncle. Pedicles without berries have a distinctive rounded five part calyx. Fruits are round with a flat indented top and bottom. Immature berries are green, turning white and then blackish purple.

Root: Thick central taproot which grows deep and spreads horizontally. Rapid growth. Tan cortex, white pulp, moderate number of rootlets. Transversely cut root slices show concentric rings. No nitrogen fixation ability.^[1][5]

Habitat and range

Broadly distributed in fields and waste places, and usually found in edge habitats. The seeds do not require stratification and are dispersed by berry-feeding birds. Adapted to coarse or fine soils with moderate moisture, high calcium tolerance but low salinity tolerance, pH tolerance from 4.7-8. Grows well in sun or shade and readily survives fire due to its ability to resprout from the roots. In recent years the plant appears to have increased in populated places. Found in most of the United States except the Mountain States, Alaska and Hawaii.^[1][6]

Known constituents

Various sources discuss notable chemical constituents of the plant.^[1][7]

Triterpene saponins: Phytolaccoside A,B,C,D,E,F,G (esculentoside E), phytolaccagenin, jaligonic acid, esculentic acid, 3-oxo-30-carbomethoxy-23-norolean-12-en-28-oic acid, phytolaccagenic acid, oleanolic acid.^[8]

Triterpene alcohols: α-spinasterol, α-spinasteryl-β-D-glucoside, 6-palmityl-Δ7-stigmasterol-Δ-D-glucoside, 6-palmytityl-α-spinasteryl-6-D-glucoside.

Others: phytolaccatoxin, canthomicrol, astragalin, protein PAP-R, Pokeweed mitogen, (PMW, a series of glycoproteins), caryophyllene, lectins, tannin, starch.

Nutritional information per 100 grams dry weight of shoots:^[5]

• Protein: 31 g; fat: 4.8 g; carbohydrates: 44 g; fiber: 0 g; ash: 20.2 g
• Minerals - calcium: 631 mg; phosphorus: 524 mg; iron: 20.2 mg; magnesium: 0 mg; sodium: 0 mg; potassium: 0 mg; zinc: 0 mg
• Vitamins - vitamin A: 62 mg; thiamine (vitamin B₁): 0.95 mg; riboflavin (vitamin B₂): 3.93 mg; niacin (vitamin B₃): 14.3 mg; vitamin B₆: 0 mg; vitamin C: 1619 mg

Standardization: Phytolacca is not generally standardized since it is not marketed to public and various properties are being considered for standardization for different uses.

Toxicity

Pokeweed poisonings were common in eastern North America during the 19th century, especially from the use of tinctures as antirheumatic preparations and from ingestion of berries and roots that were mistaken for parsnip, Jerusalem artichoke, or horseradish.^[9] Deaths are currently uncommon, although there are cases of emesis and catharsis, but at least one death of a child who consumed crushed seeds in a juice has occurred.

Toxic components of the plant include saponins based on the triterepene genins phytolaccagenin, jaligonic acid, phytolaccagenic acid (phytolaccinic acid), esculentic acid, and pokeberrygenin.^[8] These include phytolaccosides A, B, D, E, and G, and phytolaccasaponins B, E, and G. Phytolaccigenin causes hemagglutination.^[10][11] Additional toxic constituents which have been identified include the alkaloids phytolaccine and phytolaccotoxin, as well as a glycoprotein.^[12]

The poisonous principles are found in highest concentrations in the rootstock, leaves, and stems while only small amounts are in the ripe fruits.^[13] The plant generally gets more toxic with maturity with the exception of the berries which are more toxic while still green.^[14]

Symptoms of poisoning from common pokeweed include a burning sensation in the mouth, salivation, gastrointestinal cramps, vomiting and bloody diarrhea. Depending upon the amount consumed more severe symptoms can occur. These include: anemia, altered heart rate and respiration, convulsions and death from respiratory failure. In most cases both people and animals recover within 1 to 2 days if only small quantities are eaten.^[15]

A 1962 study concluded that the oral lethal dose of fresh poke berries in mice "appeared to be about 300 gm/kg body weight and for the dry berries about 100 gm/kg body weight." and that the "liquid extract of Poke berries was approximately 80 times as toxic when injected intraperitoneally as when given orally".^[16]

Uses

Phytolacca americana is used as a folk medicine and as food, although all parts of it are to be considered toxic unless properly prepared. The root is never eaten and cannot be made edible.^[17]

Food uses

The leaves of young plants are sometimes collected as a spring green potherb and eaten after repeated blanchings. Shoots are also blanched with several changes of water and eaten as a substitute for asparagus. They become cathartic as they advance to maturity.^[18]

Young leaves, if collected before acquiring a red color, are said by some to be edible if boiled for 5 minutes, rinsed, and reboiled. However, it may be difficult to identify exactly when leaves have no red color whatsoever; an incorrect picking may result in a poisoning. Berries are toxic when raw but cooked juice is reportedly potable, whereas the seeds are supposed to remain toxic after cooking. Pokeberry juice is added to other juices for jelly by those who believe it can relieve the pain of arthritis. In a traditional Cherokee recipe for fried poke stalks, young stalks are harvested while still tender, peeled to remove most of the toxin, washed, then cut into pieces and fried like okra with cornmeal.

Young pokeweed leaves boiled three times to reduce the toxin, discarding the water after each boiling, results in "poke salit" "poke salad", or "poke sallet",^[19][20] and is occasionally available commercially. Many authorities advise against eating pokeweed even after thrice boiling, as traces of the toxin may still remain. All agree pokeweed should never be eaten uncooked. The cultural significance of poke salad is referenced in the 1969 hit song "Polk Salad Annie", written and performed by Tony Joe White, and famously covered by Elvis Presley, as well as other bands such as the El Orbits of Houston, Texas. Poke sallet festivals are held annually in Gainesboro, Tennessee; Blanchard, Louisiana; Harlan, Kentucky and Arab, Alabama.

The juice from the berries can be used to make jelly. The berries have also been used to make pies.^[15][21]

Medicinal uses

Historically pokeweed has been used as a folk remedy by Native Americans as a purgative, an emetic, a heart stimulant and to treat cancer, itching, and syphilis. It was also used for its anti-rheumatic properties and in 1820 the US Pharmacopoeia listed this plant as an analgesic and anti-inflammatory.^[1][22][23] Preliminary in vitro studies on a protein isolated from pokeweed indicate activity against HIV and some types of cancer cells, but its effectiveness in human health has not yet been examined.^[23]

Other uses

A patent has been filed to use poke toxins to control zebra mussels.^[24]

Some pokeweeds are also grown as ornamental plants, mainly for their attractive berries; a number of cultivars have been selected for larger fruit panicles.

Pokeweeds are used as food plants by the larvae of some Lepidoptera species including giant leopard moth.

Pokeweed berries can be processed to yield a red ink or dye.^[25][26]

Gallery

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  Berries

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  Ripe fruit

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  Flower

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  Young fruit

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  Brush

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  Unopened flower buds

Wikimedia Commons has media related to Phytolacca americana.

References

• Elvin-Lewis, Memory P. F.; Lewis, Walter Hepworth (2003). Medical botany: plants affecting human health (2nd ed.). Chichester: John Wiley & Sons. p. 82. ISBN 0-471-62882-4. 
• "Complete Pokeweed Information" from Drugs.com professional

External links

• HikeArizona.COM: Phytolacca americana
• Phytolacca americana in the Flora of North America
• Phytolacca americana in John Uri Lloyd's Kings American Dispensatory
• Phytolacca americana in Finley Ellingwood's The American Materia Medica, Therapeutics and Pharmacognosy.
• Felter's Materia Medica